Conventionally, radiation therapies are carried out over one or a successive series of treatment sessions. For certain radiation therapies, high-energy photons and/or electrons are carefully directed and/or focused from an ex vivo radiation source so that they travel into a targeted treatment area in a patient's body. In other radiation therapies, the radiation is delivered internally via planted radioactive seeds, radioactive analytes, and the like.
Generally stated, the size, shape, and position of the treatment area (typically where a tumor is or was) as well as its anatomical location in the body and its proximity to sensitive normal tissues are considered when generating a particular patient's treatment plan. That is, the treatment is planned so as to deliver a suitably high dose of radiation to the tumor or targeted tissue while minimizing the dose to nearby sensitive tissue that typically cannot be completely avoided. Directing radiation into non-affected regions may produce undesired side effects, particularly as it relates to tissue that may be sensitive to certain dosages of radiation. Unfortunately, even when the patient plan is carefully constructed to account for the location of the cancerous tissue and the sensitive non-affected regions, even small errors in set-up due to beam angle or patient position during delivery of the radiation therapy can inadvertently misdirect radiation into those regions or can influence the dose amount that is actually received by the targeted tissue. Further, the demand for radiation treatment equipment is typically relatively high and this demand may limit the set-up time allowed or allocated in the treatment room between patients.
In the past, implantable devices for oncology applications have been proposed to evaluate the radiation dose amount received in vivo at the tumor site. See, e.g., U.S. Pat. No. 6,402,689 to Scarantino et al., the contents of which are hereby incorporated by reference herein. Measuring the radiation at the tumor site in vivo can provide improved estimates of doses received. However, for certain tumor types or situations, alternatively configured internal radiation dosimeters may be desirable and sufficient for clinical purposes.
In view of the foregoing, there remains a need for improved economical and easy to use internal radiation dosimeters.